The principle and attention of drying treatment of electric arc furnace transformer

Problems that should be paid attention to in the drying process of electric arc furnace transformer

1. If the drying chamber is not evacuated, a vent hole should be opened on the box cover or a throttle hole should be used to release the moisture.

2. When heating with oil, an insulation layer should be installed outside the fuel tank. The insulation layer can be made of asbestos cloth, glass cloth and other insulation materials, and flammable materials should not be used, and corresponding fire prevention measures should be taken.

3. In order to increase the drying quality of the winding, there are two major factors to be considered carefully: one is to control the drying temperature; the other is to increase the vacuum degree of the equipment. Ordinary drying equipment can provide process requirements, but it is affected by many factors, and it is necessary to think about it as a whole. , reasonable arrangement to obtain a good drying effect.

4. In the process of vacuuming during drying, in the low temperature stage of drying at the beginning, it is not advisable to vacuumize or dry under low vacuum conditions, otherwise it is not conducive to the increase of core temperature and the removal of moisture. When the temperature rises to 70-80 Start to increase the vacuum degree when the temperature is Celsius. When the drying is stopped for 1-2 hours, there is more water vapor in the fuel tank, the heat radiation can rise, the temperature inside tends to be average, the moisture is gradually reduced, and the heat radiation can be reduced again.

5. The method of verifying the insulation after drying and the technical indicators of the transformer tested. After it is dried, its insulation performance needs to be verified once to check its drying effect. The verified items, except for the bushing, are all It is the same as the experimental item during the overhaul of the hanging heart.

The main factors affecting the drying effect of transformers

1. There must be more heat energy. A large electric arc furnace transformer has several tons of insulators and contains a lot of moisture, so a considerable amount of heat energy is required in the drying process.

2. The greater the partial pressure difference of water vapor between the insulating material and the 4-week medium, the faster the moisture in the insulating material evaporates, diffuses and migrates. Reduce the partial pressure of water vapor in the insulating 4-week medium and increase the temperature of the insulating material , can increase the difference.

3. The diffusion coefficient of the insulating material depends on the moisture content, temperature and air pressure of the insulating material for 4 weeks.

4. The drying time should be short, and the drying time mainly depends on the requested water content index.